#define _CRT_SECURE_NO_WARNINGS 1
string& insert(size_t pos, const char* str)
{
	size_t len = strlen(str);
	if (_size + len > _capacity)
	{
		reserve(_size + len);
	}

	size_t end = _size + len + 1;
	while (end > pos + len)
	{
		_str[end] = _str[end - len];
		--end;
	}
	for (int i = 0; i < len; i++)
	{
		_str[pos + i] = str[i];
	}
	

	return *this;
}